On Saturday, North Korea marked the 105th anniversary of the birth of its founding president, Kim Il-sung, with a huge military parade in Pyongyang amid speculation that current leader Kim Jong-un could order a new nuclear test.

The event, which appeared to include new intercontinental and submarine-launched ballistic missiles, was a deliberate show of strength.

Media captionNorth Korea used its military parade to send a clear message about its nuclear programme, reports John Sudworth

US Vice-President Mike Pence is flying to the South Korean capital, Seoul, where he is expected to discuss the best way to deal with North Korea’s missile and nuclear programmes.

On a long-planned 10-day trip to Asia, his first official visit to the region, Mr Pence will reaffirm the US commitment to stand by its regional allies, officials say.

It comes as Washington steps up the pressure on the isolated North, with President Donald Trump saying that the US is ready to act alone to deal with the nuclear threat.

At the parade on Saturday, North Korean military official Choe Ryong-hae, who is believed to be the country’s second most powerful official, said that his country was “prepared to respond to an all-out war with an all-out war”.

“We are ready to hit back with nuclear attacks of our own style against any nuclear attacks,” he said.